Maintaining a shared hosting server is a full time job but tools and proper checks and balances can help make this burden lot less. I manage a shared hosting server for one of my friends and numerous times the scripts that people have installed over on their websites have vulnerabilities and hackers exploit it to upload stuff that mass-email or do other nasty stuff. Luckily, most of these exploits have common patterns like files names or other signatures that make them traceable (most of the time the so called hackers are just kiddy scripts) Create a file and put this in it [code]#!/bin/bash find /home -name 'paypal.com*' | mail -s '[Woodcrest] Phishing Alert!' me@mydomain.com find /home -name 'rout.php' | mail -s '[Woodcrest] Phishing Alert - Mail Bomber!' me@mydomain.com[/code] This is…

I tried to do package-cleanup and found this [code highlight="2"]root@ns1 [~]# package-cleanup --problems -bash: package-cleanup: command not found[/code] If I was on Ubuntu, I would have done "apt-get install package-cleanup" but it does not work that way on CentOS, its actually available in yum-utils package, install it by typing [code]yum install yum-utils[/code] Enjoy!!

The greatest fear with adding additional and especially third party repos such as EPEL (we did a blog post on how to install EPEL earlier) is that it MAY overwrite base packages and bring the system to an unstable state. We can fix this issue by installing Yum Priorities plugin on CentOS 5: [code]yum install yum-priorities[/code] on CentOS 4 or CentOS 6: [code]yum install yum-plugin-priorities[/code] Then make sure that the plugin is enabled [code]nano /etc/yum/pluginconf.d/priorities.conf[/code] Now there are two ways to do it, either set HIGHEST priority to CentOS repos OR set lowest priority to other repos. This is done by adding the line [code highlight="3"] # N=1 highest priority # N=99 lowest priority priority=N [/code] In this blog post, I will set 1 as the priority (highest) for my…

SELINUX is a security feature on CentOS but some software such as SolusVM will require that SELINUX be disabled [code] Installation log : /tmp/install.log Add this slave to your SolusVM master using the following details: ID Key .......... : ABC ID Password ..... : XYZ IMPORTANT!! You need to setup a network bridge before you can use KVM on this server. Please see the following link: http://wiki.solusvm.com/index.php/KVM_Network_Bridge_Setup Please set SELINUX=disabled in /etc/selinux/config before rebooting. Thankyou for choosing SolusVM. [/code] The solution? 1) Edit /etc/selinux/config using your favourite editor [code][root@kvm ~]# nano /etc/selinux/config[/code] and set SELINUX=disabled [code highlight="6"]# This file controls the state of SELinux on the system. # SELINUX= can take one of these three values: # enforcing - SELinux security policy is enforced. # permissive - SELinux prints warnings…

Normally, I have two things on every Linux box so that I know whats going on NAGIOS monitoring (nrpe) Logwatch Today, I got something in my logwatch email and it was strange because just the other day, I upgraded the clamav to latest version using epel reo. [code title="This is what I got in logwatch today" highlight="3,4,5"] --------------------- clam-update Begin ------------------------ The ClamAV update process (freshclam daemon) was not running! If you no longer wish to run freshclam, deleting the freshclam.log file will suppress this error message. ---------------------- clam-update End ------------------------- [/code] It appears that the latest version has some permission issues on the log file because when I try to run freshclam on command line I get this [code]root@cpanel [~]# freshclam ERROR: Can't open /var/log/clamav/freshclam.log in append mode (check…

[caption id="attachment_1147" align="aligncenter" width="300" caption="htop - an alternative to linux top"][/caption] htop is a sleek utility that allows you to interactively view processes running in a linux box. I can safely say its a good alternate to 'top' To install htop just run this after installing epel repo [code]yum install htop[/code]

Installing EPEL repo in CentOS is simple, if you do not know what EPEL is, read more about it here. [code]rpm -Uvh http://download.fedora.redhat.com/pub/epel/5/i386/epel-release-5-4.noarch.rpm[/code] To configure epel or disable it use [code]nano /etc/yum.repos.d/epel.repo[/code] and then switch the config enabled to 0 (or vice versa) Don't forget to do the following [code]yum clean all[/code]

I always had the question (when I am running plenty of scripts on a linux box as to what is eating up all the memory? Finding memory consumed by current running processes in your favorite linux distro. Luckily, I found a great Python utility (scriplet to be exact). (more…)